diff --git a/packages/react-server-dom-fb/src/ReactFlightReferencesFB.js b/packages/react-server-dom-fb/src/ReactFlightReferencesFB.js
index 561ec56c79eb5..a8ed6f357a20b 100644
--- a/packages/react-server-dom-fb/src/ReactFlightReferencesFB.js
+++ b/packages/react-server-dom-fb/src/ReactFlightReferencesFB.js
@@ -10,7 +10,7 @@
 export type ClientManifest = null;
 
 // eslint-disable-next-line no-unused-vars
-export type ServerReference<T> = string;
+export type ServerReference<T> = {};
 
 // eslint-disable-next-line no-unused-vars
 export type ClientReference<T> = {
diff --git a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js
index 5d966a16ded59..13b9a16338827 100644
--- a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js
+++ b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js
@@ -225,6 +225,37 @@ describe('ReactFlightDOMEdge', () => {
     const stream = ReactServerDOMServer.renderToReadableStream(children);
     const [stream1, stream2] = passThrough(stream).tee();
 
+    const serializedContent = await readResult(stream1);
+
+    expect(serializedContent.length).toBeLessThan(400);
+    expect(timesRendered).toBeLessThan(5);
+
+    const result = await ReactServerDOMClient.createFromReadableStream(
+      stream2,
+      {
+        ssrManifest: {
+          moduleMap: null,
+          moduleLoading: null,
+        },
+      },
+    );
+    // Should still match the result when parsed
+    expect(result).toEqual(resolvedChildren);
+  });
+
+  it('should execute repeated host components only once', async () => {
+    const div = <div>this is a long return value</div>;
+    let timesRendered = 0;
+    function ServerComponent() {
+      timesRendered++;
+      return div;
+    }
+    const element = <ServerComponent />;
+    const children = new Array(30).fill(element);
+    const resolvedChildren = new Array(30).fill(div);
+    const stream = ReactServerDOMServer.renderToReadableStream(children);
+    const [stream1, stream2] = passThrough(stream).tee();
+
     const serializedContent = await readResult(stream1);
     expect(serializedContent.length).toBeLessThan(400);
     expect(timesRendered).toBeLessThan(5);
diff --git a/packages/react-server/src/ReactFlightServer.js b/packages/react-server/src/ReactFlightServer.js
index 5263d01611c52..86f686ce757fb 100644
--- a/packages/react-server/src/ReactFlightServer.js
+++ b/packages/react-server/src/ReactFlightServer.js
@@ -325,6 +325,10 @@ export function createRequest(
     rootContext,
     abortSet,
   );
+  // TODO
+  if (model !== null && typeof model === 'object') {
+    request.writtenObjects.set(model, rootTask.id);
+  }
   pingedTasks.push(rootTask);
   return request;
 }
@@ -787,10 +791,6 @@ function createTask(
   abortSet: Set<Task>,
 ): Task {
   const id = request.nextChunkId++;
-  if (typeof model === 'object' && model !== null) {
-    // Register this model as having the ID we're about to write.
-    request.writtenObjects.set(model, id);
-  }
   const task: Task = {
     id,
     status: PENDING,
@@ -988,7 +988,17 @@ function serializeClientReference(
   }
 }
 
-function outlineModel(request: Request, value: ReactClientValue): number {
+function outlineModel(
+  request: Request,
+  value:
+    | ClientReference<any>
+    | ServerReference<any>
+    | Iterable<ReactClientValue>
+    | Array<ReactClientValue>
+    | Map<ReactClientValue, ReactClientValue>
+    | Set<ReactClientValue>
+    | ReactClientObject,
+): number {
   request.pendingChunks++;
   const newTask = createTask(
     request,
@@ -998,6 +1008,7 @@ function outlineModel(request: Request, value: ReactClientValue): number {
     rootContextSnapshot, // Therefore we don't pass any contextual information along.
     request.abortableTasks,
   );
+  request.writtenObjects.set(value, newTask.id);
   retryTask(request, newTask);
   return newTask.id;
 }
@@ -1251,9 +1262,18 @@ function renderModelDestructive(
         const writtenObjects = request.writtenObjects;
         const existingId = writtenObjects.get(value);
         if (existingId !== undefined) {
-          if (existingId === -1) {
+          if (
+            enableServerComponentKeys &&
+            (task.keyPath !== null ||
+              task.implicitSlot ||
+              task.context !== rootContextSnapshot)
+          ) {
+            // If we're in some kind of context we can't reuse the result of this render or
+            // previous renders of this element. We only reuse elements if they're not wrapped
+            // by another Server Component.
+          } else if (existingId === -1) {
             // Seen but not yet outlined.
-            const newId = outlineModel(request, value);
+            const newId = outlineModel(request, (value: any));
             return serializeByValueID(newId);
           } else if (modelRoot === value) {
             // This is the ID we're currently emitting so we need to write it
@@ -1359,7 +1379,7 @@ function renderModelDestructive(
     if (existingId !== undefined) {
       if (existingId === -1) {
         // Seen but not yet outlined.
-        const newId = outlineModel(request, value);
+        const newId = outlineModel(request, (value: any));
         return serializeByValueID(newId);
       } else if (modelRoot === value) {
         // This is the ID we're currently emitting so we need to write it
diff --git a/packages/react-server/src/ReactFlightServerConfigBundlerCustom.js b/packages/react-server/src/ReactFlightServerConfigBundlerCustom.js
index b1fbc93ee61b1..d30365a73211d 100644
--- a/packages/react-server/src/ReactFlightServerConfigBundlerCustom.js
+++ b/packages/react-server/src/ReactFlightServerConfigBundlerCustom.js
@@ -9,9 +9,11 @@
 
 declare var $$$config: any;
 
+interface Reference {}
+
 export opaque type ClientManifest = mixed;
-export opaque type ClientReference<T> = mixed; // eslint-disable-line no-unused-vars
-export opaque type ServerReference<T> = mixed; // eslint-disable-line no-unused-vars
+export opaque type ClientReference<T>: Reference = Reference; // eslint-disable-line no-unused-vars
+export opaque type ServerReference<T>: Reference = Reference; // eslint-disable-line no-unused-vars
 export opaque type ClientReferenceMetadata: any = mixed;
 export opaque type ServerReferenceId: any = mixed;
 export opaque type ClientReferenceKey: any = mixed;